[BMIM]Cl concentration-regulated wet ball milling of coconut pomace cellulose: Structural modification-driven enhancement of Pickering emulsion stability

• Wet milling in ionic liquid accelerates nanocellulose formation efficiently. • [BMIM]Cl concentration regulates hydrogen bonding to yield amphiphilic cellulose surfaces. • BM-ILs12 exhibited the best emulsifying properties. • Nanocellulose forms viscoelastic layers stabilizing Pickering emulsions. • Green valorization of coconut pomace cellulose into efficient food-grade stabilizers. Coconut pomace, an abundant by-product of coconut milk production, is an underutilized source of cellulose. To enhance its functionality, a green modification approach was developed using wet ball milling in 1-Butyl-3-methylimidazolium chloride ([BMIM]Cl) at different concentrations (0–12%) to investigate the effects of ionic liquid concentration on the structural and emulsifying properties of coconut pomace nanocellulose. Increasing [BMIM]Cl concentration effectively reduced cellulose particle size to a minimum of 323 nm and increased absolute zeta potential. Structural analysis confirmed the disruption of intra-fibrillar hydrogen bonding and a reduction in crystallinity, which collectively resulted in more hydrophobic and flexible cellulose surfaces. These structural transformations led to significantly improved water-holding capacity, oil-binding capacity, and emulsifying properties. In Pickering emulsion applications, the modified coconut pomace cellulose formed viscoelastic interfacial layers and robust three-dimensional networks, yielding emulsions with smaller droplet size, higher viscosity, and superior centrifugal stability. These findings establish a concentration-dependent approach for valorizing coconut pomace cellulose into a sustainable and high-performance Pickering stabilizer, offering new insights into green modification strategies for potential food-grade stabilizers.